The aim of this study is to determine the specific sites of pancreas histone F1 phosphorylation during regeneration and in the early stages of carcinogenesis. Surgical resection will be used to reduce the amount of rat pancreas. Asaserine and 4-hydroxyaminoquinoline-1-oxide will be used as pancreas carcinogens. At various intervals after treatment,experimental and control animals will be injected with P32. After one hour the animals are sacrificed and histones and the Fl fraction are prepared from the pancreas. Fl histone is digested with trypsin, and peptide maps made to determine which peptides are phosphorylated.